xref: /linux/drivers/scsi/NCR5380.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  * NCR 5380 generic driver routines.  These should make it *trivial*
3  *      to implement 5380 SCSI drivers under Linux with a non-trantor
4  *      architecture.
5  *
6  *      Note that these routines also work with NR53c400 family chips.
7  *
8  * Copyright 1993, Drew Eckhardt
9  *      Visionary Computing
10  *      (Unix and Linux consulting and custom programming)
11  *      drew@colorado.edu
12  *      +1 (303) 666-5836
13  *
14  * DISTRIBUTION RELEASE 6.
15  *
16  * For more information, please consult
17  *
18  * NCR 5380 Family
19  * SCSI Protocol Controller
20  * Databook
21  *
22  * NCR Microelectronics
23  * 1635 Aeroplaza Drive
24  * Colorado Springs, CO 80916
25  * 1+ (719) 578-3400
26  * 1+ (800) 334-5454
27  */
28 
29 /*
30  * $Log: NCR5380.c,v $
31 
32  * Revision 1.10 1998/9/2	Alan Cox
33  *				(alan@redhat.com)
34  * Fixed up the timer lockups reported so far. Things still suck. Looking
35  * forward to 2.3 and per device request queues. Then it'll be possible to
36  * SMP thread this beast and improve life no end.
37 
38  * Revision 1.9  1997/7/27	Ronald van Cuijlenborg
39  *				(ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
40  * (hopefully) fixed and enhanced USLEEP
41  * added support for DTC3181E card (for Mustek scanner)
42  *
43 
44  * Revision 1.8			Ingmar Baumgart
45  *				(ingmar@gonzo.schwaben.de)
46  * added support for NCR53C400a card
47  *
48 
49  * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
50  * added proc_info
51  * added support needed for DTC 3180/3280
52  * fixed a couple of bugs
53  *
54 
55  * Revision 1.5  1994/01/19  09:14:57  drew
56  * Fixed udelay() hack that was being used on DATAOUT phases
57  * instead of a proper wait for the final handshake.
58  *
59  * Revision 1.4  1994/01/19  06:44:25  drew
60  * *** empty log message ***
61  *
62  * Revision 1.3  1994/01/19  05:24:40  drew
63  * Added support for TCR LAST_BYTE_SENT bit.
64  *
65  * Revision 1.2  1994/01/15  06:14:11  drew
66  * REAL DMA support, bug fixes.
67  *
68  * Revision 1.1  1994/01/15  06:00:54  drew
69  * Initial revision
70  *
71  */
72 
73 /*
74  * Further development / testing that should be done :
75  * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
76  *     code so that everything does the same thing that's done at the
77  *     end of a pseudo-DMA read operation.
78  *
79  * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
80  *     basically, transfer size needs to be reduced by one
81  *     and the last byte read as is done with PSEUDO_DMA.
82  *
83  * 4.  Test SCSI-II tagged queueing (I have no devices which support
84  *      tagged queueing)
85  *
86  * 5.  Test linked command handling code after Eric is ready with
87  *      the high level code.
88  */
89 #include <scsi/scsi_dbg.h>
90 #include <scsi/scsi_transport_spi.h>
91 
92 #ifndef NDEBUG
93 #define NDEBUG 0
94 #endif
95 #ifndef NDEBUG_ABORT
96 #define NDEBUG_ABORT 0
97 #endif
98 
99 #if (NDEBUG & NDEBUG_LISTS)
100 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
101 #define REMOVE(w,x,y,z) {printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
102 #else
103 #define LIST(x,y)
104 #define REMOVE(w,x,y,z)
105 #endif
106 
107 #ifndef notyet
108 #undef LINKED
109 #undef REAL_DMA
110 #endif
111 
112 #ifdef REAL_DMA_POLL
113 #undef READ_OVERRUNS
114 #define READ_OVERRUNS
115 #endif
116 
117 #ifdef BOARD_REQUIRES_NO_DELAY
118 #define io_recovery_delay(x)
119 #else
120 #define io_recovery_delay(x)	udelay(x)
121 #endif
122 
123 /*
124  * Design
125  *
126  * This is a generic 5380 driver.  To use it on a different platform,
127  * one simply writes appropriate system specific macros (ie, data
128  * transfer - some PC's will use the I/O bus, 68K's must use
129  * memory mapped) and drops this file in their 'C' wrapper.
130  *
131  * (Note from hch:  unfortunately it was not enough for the different
132  * m68k folks and instead of improving this driver they copied it
133  * and hacked it up for their needs.  As a consequence they lost
134  * most updates to this driver.  Maybe someone will fix all these
135  * drivers to use a common core one day..)
136  *
137  * As far as command queueing, two queues are maintained for
138  * each 5380 in the system - commands that haven't been issued yet,
139  * and commands that are currently executing.  This means that an
140  * unlimited number of commands may be queued, letting
141  * more commands propagate from the higher driver levels giving higher
142  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
143  * allowing multiple commands to propagate all the way to a SCSI-II device
144  * while a command is already executing.
145  *
146  *
147  * Issues specific to the NCR5380 :
148  *
149  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
150  * piece of hardware that requires you to sit in a loop polling for
151  * the REQ signal as long as you are connected.  Some devices are
152  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
153  * while doing long seek operations.
154  *
155  * The workaround for this is to keep track of devices that have
156  * disconnected.  If the device hasn't disconnected, for commands that
157  * should disconnect, we do something like
158  *
159  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
160  *
161  * Some tweaking of N and M needs to be done.  An algorithm based
162  * on "time to data" would give the best results as long as short time
163  * to datas (ie, on the same track) were considered, however these
164  * broken devices are the exception rather than the rule and I'd rather
165  * spend my time optimizing for the normal case.
166  *
167  * Architecture :
168  *
169  * At the heart of the design is a coroutine, NCR5380_main,
170  * which is started from a workqueue for each NCR5380 host in the
171  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
172  * removing the commands from the issue queue and calling
173  * NCR5380_select() if a nexus is not established.
174  *
175  * Once a nexus is established, the NCR5380_information_transfer()
176  * phase goes through the various phases as instructed by the target.
177  * if the target goes into MSG IN and sends a DISCONNECT message,
178  * the command structure is placed into the per instance disconnected
179  * queue, and NCR5380_main tries to find more work.  If the target is
180  * idle for too long, the system will try to sleep.
181  *
182  * If a command has disconnected, eventually an interrupt will trigger,
183  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
184  * to reestablish a nexus.  This will run main if necessary.
185  *
186  * On command termination, the done function will be called as
187  * appropriate.
188  *
189  * SCSI pointers are maintained in the SCp field of SCSI command
190  * structures, being initialized after the command is connected
191  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
192  * Note that in violation of the standard, an implicit SAVE POINTERS operation
193  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
194  */
195 
196 /*
197  * Using this file :
198  * This file a skeleton Linux SCSI driver for the NCR 5380 series
199  * of chips.  To use it, you write an architecture specific functions
200  * and macros and include this file in your driver.
201  *
202  * These macros control options :
203  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
204  *      defined.
205  *
206  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
207  *      for commands that return with a CHECK CONDITION status.
208  *
209  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
210  *      transceivers.
211  *
212  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
213  *      override-configure an IRQ.
214  *
215  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
216  *      bytes at a time.  Since interrupts are disabled by default during
217  *      these transfers, we might need this to give reasonable interrupt
218  *      service time if the transfer size gets too large.
219  *
220  * LINKED - if defined, linked commands are supported.
221  *
222  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
223  *
224  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
225  *
226  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
227  *      rely on phase mismatch and EOP interrupts to determine end
228  *      of phase.
229  *
230  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
231  *          only really want to use this if you're having a problem with
232  *          dropped characters during high speed communications, and even
233  *          then, you're going to be better off twiddling with transfersize
234  *          in the high level code.
235  *
236  * Defaults for these will be provided although the user may want to adjust
237  * these to allocate CPU resources to the SCSI driver or "real" code.
238  *
239  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
240  *
241  * USLEEP_POLL - amount of time, in jiffies, to poll
242  *
243  * These macros MUST be defined :
244  * NCR5380_local_declare() - declare any local variables needed for your
245  *      transfer routines.
246  *
247  * NCR5380_setup(instance) - initialize any local variables needed from a given
248  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
249  *
250  * NCR5380_read(register)  - read from the specified register
251  *
252  * NCR5380_write(register, value) - write to the specific register
253  *
254  * NCR5380_implementation_fields  - additional fields needed for this
255  *      specific implementation of the NCR5380
256  *
257  * Either real DMA *or* pseudo DMA may be implemented
258  * REAL functions :
259  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
260  * Note that the DMA setup functions should return the number of bytes
261  *      that they were able to program the controller for.
262  *
263  * Also note that generic i386/PC versions of these macros are
264  *      available as NCR5380_i386_dma_write_setup,
265  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
266  *
267  * NCR5380_dma_write_setup(instance, src, count) - initialize
268  * NCR5380_dma_read_setup(instance, dst, count) - initialize
269  * NCR5380_dma_residual(instance); - residual count
270  *
271  * PSEUDO functions :
272  * NCR5380_pwrite(instance, src, count)
273  * NCR5380_pread(instance, dst, count);
274  *
275  * The generic driver is initialized by calling NCR5380_init(instance),
276  * after setting the appropriate host specific fields and ID.  If the
277  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
278  * possible) function may be used.
279  */
280 
281 static int do_abort(struct Scsi_Host *host);
282 static void do_reset(struct Scsi_Host *host);
283 
284 /*
285  *	initialize_SCp		-	init the scsi pointer field
286  *	@cmd: command block to set up
287  *
288  *	Set up the internal fields in the SCSI command.
289  */
290 
291 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
292 {
293 	/*
294 	 * Initialize the Scsi Pointer field so that all of the commands in the
295 	 * various queues are valid.
296 	 */
297 
298 	if (cmd->use_sg) {
299 		cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
300 		cmd->SCp.buffers_residual = cmd->use_sg - 1;
301 		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
302 			       cmd->SCp.buffer->offset;
303 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
304 	} else {
305 		cmd->SCp.buffer = NULL;
306 		cmd->SCp.buffers_residual = 0;
307 		cmd->SCp.ptr = (char *) cmd->request_buffer;
308 		cmd->SCp.this_residual = cmd->request_bufflen;
309 	}
310 }
311 
312 /**
313  *	NCR5380_poll_politely	-	wait for NCR5380 status bits
314  *	@instance: controller to poll
315  *	@reg: 5380 register to poll
316  *	@bit: Bitmask to check
317  *	@val: Value required to exit
318  *
319  *	Polls the NCR5380 in a reasonably efficient manner waiting for
320  *	an event to occur, after a short quick poll we begin giving the
321  *	CPU back in non IRQ contexts
322  *
323  *	Returns the value of the register or a negative error code.
324  */
325 
326 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
327 {
328 	NCR5380_local_declare();
329 	int n = 500;		/* At about 8uS a cycle for the cpu access */
330 	unsigned long end = jiffies + t;
331 	int r;
332 
333 	NCR5380_setup(instance);
334 
335 	while( n-- > 0)
336 	{
337 		r = NCR5380_read(reg);
338 		if((r & bit) == val)
339 			return 0;
340 		cpu_relax();
341 	}
342 
343 	/* t time yet ? */
344 	while(time_before(jiffies, end))
345 	{
346 		r = NCR5380_read(reg);
347 		if((r & bit) == val)
348 			return 0;
349 		if(!in_interrupt())
350 			yield();
351 		else
352 			cpu_relax();
353 	}
354 	return -ETIMEDOUT;
355 }
356 
357 static struct {
358 	unsigned char value;
359 	const char *name;
360 } phases[] = {
361 	{PHASE_DATAOUT, "DATAOUT"},
362 	{PHASE_DATAIN, "DATAIN"},
363 	{PHASE_CMDOUT, "CMDOUT"},
364 	{PHASE_STATIN, "STATIN"},
365 	{PHASE_MSGOUT, "MSGOUT"},
366 	{PHASE_MSGIN, "MSGIN"},
367 	{PHASE_UNKNOWN, "UNKNOWN"}
368 };
369 
370 #if NDEBUG
371 static struct {
372 	unsigned char mask;
373 	const char *name;
374 } signals[] = {
375 	{SR_DBP, "PARITY"},
376 	{SR_RST, "RST"},
377 	{SR_BSY, "BSY"},
378 	{SR_REQ, "REQ"},
379 	{SR_MSG, "MSG"},
380 	{SR_CD, "CD"},
381 	{SR_IO, "IO"},
382 	{SR_SEL, "SEL"},
383 	{0, NULL}
384 },
385 basrs[] = {
386 	{BASR_ATN, "ATN"},
387 	{BASR_ACK, "ACK"},
388 	{0, NULL}
389 },
390 icrs[] = {
391 	{ICR_ASSERT_RST, "ASSERT RST"},
392 	{ICR_ASSERT_ACK, "ASSERT ACK"},
393 	{ICR_ASSERT_BSY, "ASSERT BSY"},
394 	{ICR_ASSERT_SEL, "ASSERT SEL"},
395 	{ICR_ASSERT_ATN, "ASSERT ATN"},
396 	{ICR_ASSERT_DATA, "ASSERT DATA"},
397 	{0, NULL}
398 },
399 mrs[] = {
400 	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
401 	{MR_TARGET, "MODE TARGET"},
402 	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
403 	{MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
404 	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
405 	{MR_DMA_MODE, "MODE DMA"},
406 	{MR_ARBITRATE, "MODE ARBITRATION"},
407 	{0, NULL}
408 };
409 
410 /**
411  *	NCR5380_print	-	print scsi bus signals
412  *	@instance:	adapter state to dump
413  *
414  *	Print the SCSI bus signals for debugging purposes
415  *
416  *	Locks: caller holds hostdata lock (not essential)
417  */
418 
419 static void NCR5380_print(struct Scsi_Host *instance)
420 {
421 	NCR5380_local_declare();
422 	unsigned char status, data, basr, mr, icr, i;
423 	NCR5380_setup(instance);
424 
425 	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
426 	status = NCR5380_read(STATUS_REG);
427 	mr = NCR5380_read(MODE_REG);
428 	icr = NCR5380_read(INITIATOR_COMMAND_REG);
429 	basr = NCR5380_read(BUS_AND_STATUS_REG);
430 
431 	printk("STATUS_REG: %02x ", status);
432 	for (i = 0; signals[i].mask; ++i)
433 		if (status & signals[i].mask)
434 			printk(",%s", signals[i].name);
435 	printk("\nBASR: %02x ", basr);
436 	for (i = 0; basrs[i].mask; ++i)
437 		if (basr & basrs[i].mask)
438 			printk(",%s", basrs[i].name);
439 	printk("\nICR: %02x ", icr);
440 	for (i = 0; icrs[i].mask; ++i)
441 		if (icr & icrs[i].mask)
442 			printk(",%s", icrs[i].name);
443 	printk("\nMODE: %02x ", mr);
444 	for (i = 0; mrs[i].mask; ++i)
445 		if (mr & mrs[i].mask)
446 			printk(",%s", mrs[i].name);
447 	printk("\n");
448 }
449 
450 
451 /*
452  *	NCR5380_print_phase	-	show SCSI phase
453  *	@instance: adapter to dump
454  *
455  * 	Print the current SCSI phase for debugging purposes
456  *
457  *	Locks: none
458  */
459 
460 static void NCR5380_print_phase(struct Scsi_Host *instance)
461 {
462 	NCR5380_local_declare();
463 	unsigned char status;
464 	int i;
465 	NCR5380_setup(instance);
466 
467 	status = NCR5380_read(STATUS_REG);
468 	if (!(status & SR_REQ))
469 		printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
470 	else {
471 		for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
472 		printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
473 	}
474 }
475 #endif
476 
477 /*
478  * These need tweaking, and would probably work best as per-device
479  * flags initialized differently for disk, tape, cd, etc devices.
480  * People with broken devices are free to experiment as to what gives
481  * the best results for them.
482  *
483  * USLEEP_SLEEP should be a minimum seek time.
484  *
485  * USLEEP_POLL should be a maximum rotational latency.
486  */
487 #ifndef USLEEP_SLEEP
488 /* 20 ms (reasonable hard disk speed) */
489 #define USLEEP_SLEEP (20*HZ/1000)
490 #endif
491 /* 300 RPM (floppy speed) */
492 #ifndef USLEEP_POLL
493 #define USLEEP_POLL (200*HZ/1000)
494 #endif
495 #ifndef USLEEP_WAITLONG
496 /* RvC: (reasonable time to wait on select error) */
497 #define USLEEP_WAITLONG USLEEP_SLEEP
498 #endif
499 
500 /*
501  * Function : int should_disconnect (unsigned char cmd)
502  *
503  * Purpose : decide whether a command would normally disconnect or
504  *      not, since if it won't disconnect we should go to sleep.
505  *
506  * Input : cmd - opcode of SCSI command
507  *
508  * Returns : DISCONNECT_LONG if we should disconnect for a really long
509  *      time (ie always, sleep, look for REQ active, sleep),
510  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
511  *      time-to-data delay, DISCONNECT_NONE if this command would return
512  *      immediately.
513  *
514  *      Future sleep algorithms based on time to data can exploit
515  *      something like this so they can differentiate between "normal"
516  *      (ie, read, write, seek) and unusual commands (ie, * format).
517  *
518  * Note : We don't deal with commands that handle an immediate disconnect,
519  *
520  */
521 
522 static int should_disconnect(unsigned char cmd)
523 {
524 	switch (cmd) {
525 	case READ_6:
526 	case WRITE_6:
527 	case SEEK_6:
528 	case READ_10:
529 	case WRITE_10:
530 	case SEEK_10:
531 		return DISCONNECT_TIME_TO_DATA;
532 	case FORMAT_UNIT:
533 	case SEARCH_HIGH:
534 	case SEARCH_LOW:
535 	case SEARCH_EQUAL:
536 		return DISCONNECT_LONG;
537 	default:
538 		return DISCONNECT_NONE;
539 	}
540 }
541 
542 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
543 {
544 	hostdata->time_expires = jiffies + timeout;
545 	schedule_delayed_work(&hostdata->coroutine, timeout);
546 }
547 
548 
549 static int probe_irq __initdata = 0;
550 
551 /**
552  *	probe_intr	-	helper for IRQ autoprobe
553  *	@irq: interrupt number
554  *	@dev_id: unused
555  *	@regs: unused
556  *
557  *	Set a flag to indicate the IRQ in question was received. This is
558  *	used by the IRQ probe code.
559  */
560 
561 static irqreturn_t __init probe_intr(int irq, void *dev_id,
562 					struct pt_regs *regs)
563 {
564 	probe_irq = irq;
565 	return IRQ_HANDLED;
566 }
567 
568 /**
569  *	NCR5380_probe_irq	-	find the IRQ of an NCR5380
570  *	@instance: NCR5380 controller
571  *	@possible: bitmask of ISA IRQ lines
572  *
573  *	Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
574  *	and then looking to see what interrupt actually turned up.
575  *
576  *	Locks: none, irqs must be enabled on entry
577  */
578 
579 static int __init NCR5380_probe_irq(struct Scsi_Host *instance, int possible)
580 {
581 	NCR5380_local_declare();
582 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
583 	unsigned long timeout;
584 	int trying_irqs, i, mask;
585 	NCR5380_setup(instance);
586 
587 	for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
588 		if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
589 			trying_irqs |= mask;
590 
591 	timeout = jiffies + (250 * HZ / 1000);
592 	probe_irq = SCSI_IRQ_NONE;
593 
594 	/*
595 	 * A interrupt is triggered whenever BSY = false, SEL = true
596 	 * and a bit set in the SELECT_ENABLE_REG is asserted on the
597 	 * SCSI bus.
598 	 *
599 	 * Note that the bus is only driven when the phase control signals
600 	 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
601 	 * to zero.
602 	 */
603 
604 	NCR5380_write(TARGET_COMMAND_REG, 0);
605 	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
606 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
607 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
608 
609 	while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
610 		schedule_timeout_uninterruptible(1);
611 
612 	NCR5380_write(SELECT_ENABLE_REG, 0);
613 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
614 
615 	for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
616 		if (trying_irqs & mask)
617 			free_irq(i, NULL);
618 
619 	return probe_irq;
620 }
621 
622 /**
623  *	NCR58380_print_options	-	show options
624  *	@instance: unused for now
625  *
626  *	Called by probe code indicating the NCR5380 driver options that
627  *	were selected. At some point this will switch to runtime options
628  *	read from the adapter in question
629  *
630  *	Locks: none
631  */
632 
633 static void __init NCR5380_print_options(struct Scsi_Host *instance)
634 {
635 	printk(" generic options"
636 #ifdef AUTOPROBE_IRQ
637 	       " AUTOPROBE_IRQ"
638 #endif
639 #ifdef AUTOSENSE
640 	       " AUTOSENSE"
641 #endif
642 #ifdef DIFFERENTIAL
643 	       " DIFFERENTIAL"
644 #endif
645 #ifdef REAL_DMA
646 	       " REAL DMA"
647 #endif
648 #ifdef REAL_DMA_POLL
649 	       " REAL DMA POLL"
650 #endif
651 #ifdef PARITY
652 	       " PARITY"
653 #endif
654 #ifdef PSEUDO_DMA
655 	       " PSEUDO DMA"
656 #endif
657 #ifdef UNSAFE
658 	       " UNSAFE "
659 #endif
660 	    );
661 	printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
662 	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
663 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
664 		printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
665 	}
666 }
667 
668 /**
669  *	NCR5380_print_status 	-	dump controller info
670  *	@instance: controller to dump
671  *
672  *	Print commands in the various queues, called from NCR5380_abort
673  *	and NCR5380_debug to aid debugging.
674  *
675  *	Locks: called functions disable irqs
676  */
677 
678 static void NCR5380_print_status(struct Scsi_Host *instance)
679 {
680 	NCR5380_dprint(NDEBUG_ANY, instance);
681 	NCR5380_dprint_phase(NDEBUG_ANY, instance);
682 }
683 
684 /******************************************/
685 /*
686  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
687  *
688  * *buffer: I/O buffer
689  * **start: if inout == FALSE pointer into buffer where user read should start
690  * offset: current offset
691  * length: length of buffer
692  * hostno: Scsi_Host host_no
693  * inout: TRUE - user is writing; FALSE - user is reading
694  *
695  * Return the number of bytes read from or written
696  */
697 
698 #undef SPRINTF
699 #define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
700 static
701 char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
702 static
703 char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
704 static
705 char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
706 
707 static
708 int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer, char **start, off_t offset, int length, int inout)
709 {
710 	char *pos = buffer;
711 	struct NCR5380_hostdata *hostdata;
712 	Scsi_Cmnd *ptr;
713 
714 	hostdata = (struct NCR5380_hostdata *) instance->hostdata;
715 
716 	if (inout) {		/* Has data been written to the file ? */
717 #ifdef DTC_PUBLIC_RELEASE
718 		dtc_wmaxi = dtc_maxi = 0;
719 #endif
720 #ifdef PAS16_PUBLIC_RELEASE
721 		pas_wmaxi = pas_maxi = 0;
722 #endif
723 		return (-ENOSYS);	/* Currently this is a no-op */
724 	}
725 	SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
726 	if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
727 		SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
728 #ifdef DTC_PUBLIC_RELEASE
729 	SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
730 #endif
731 #ifdef T128_PUBLIC_RELEASE
732 	SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
733 #endif
734 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
735 	SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
736 #endif
737 #ifdef PAS16_PUBLIC_RELEASE
738 	SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
739 #endif
740 
741 	SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
742 	SPRINTF("io_port: %04x      ", (int) instance->io_port);
743 	if (instance->irq == SCSI_IRQ_NONE)
744 		SPRINTF("IRQ: None.\n");
745 	else
746 		SPRINTF("IRQ: %d.\n", instance->irq);
747 
748 #ifdef DTC_PUBLIC_RELEASE
749 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
750 #endif
751 #ifdef PAS16_PUBLIC_RELEASE
752 	SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
753 #endif
754 	spin_lock_irq(instance->host_lock);
755 	if (!hostdata->connected)
756 		SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
757 	else
758 		pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
759 	SPRINTF("scsi%d: issue_queue\n", instance->host_no);
760 	for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
761 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
762 
763 	SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
764 	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
765 		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
766 	spin_unlock_irq(instance->host_lock);
767 
768 	*start = buffer;
769 	if (pos - buffer < offset)
770 		return 0;
771 	else if (pos - buffer - offset < length)
772 		return pos - buffer - offset;
773 	return length;
774 }
775 
776 static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
777 {
778 	SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
779 	SPRINTF("        command = ");
780 	pos = lprint_command(cmd->cmnd, pos, buffer, length);
781 	return (pos);
782 }
783 
784 static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
785 {
786 	int i, s;
787 	pos = lprint_opcode(command[0], pos, buffer, length);
788 	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
789 		SPRINTF("%02x ", command[i]);
790 	SPRINTF("\n");
791 	return (pos);
792 }
793 
794 static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
795 {
796 	SPRINTF("%2d (0x%02x)", opcode, opcode);
797 	return (pos);
798 }
799 
800 
801 /**
802  *	NCR5380_init	-	initialise an NCR5380
803  *	@instance: adapter to configure
804  *	@flags: control flags
805  *
806  *	Initializes *instance and corresponding 5380 chip,
807  *      with flags OR'd into the initial flags value.
808  *
809  *	Notes : I assume that the host, hostno, and id bits have been
810  *      set correctly.  I don't care about the irq and other fields.
811  *
812  *	Returns 0 for success
813  *
814  *	Locks: interrupts must be enabled when we are called
815  */
816 
817 static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
818 {
819 	NCR5380_local_declare();
820 	int i, pass;
821 	unsigned long timeout;
822 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
823 
824 	if(in_interrupt())
825 		printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
826 	/*
827 	 * On NCR53C400 boards, NCR5380 registers are mapped 8 past
828 	 * the base address.
829 	 */
830 
831 #ifdef NCR53C400
832 	if (flags & FLAG_NCR53C400)
833 		instance->NCR5380_instance_name += NCR53C400_address_adjust;
834 #endif
835 
836 	NCR5380_setup(instance);
837 
838 	hostdata->aborted = 0;
839 	hostdata->id_mask = 1 << instance->this_id;
840 	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
841 		if (i > hostdata->id_mask)
842 			hostdata->id_higher_mask |= i;
843 	for (i = 0; i < 8; ++i)
844 		hostdata->busy[i] = 0;
845 #ifdef REAL_DMA
846 	hostdata->dmalen = 0;
847 #endif
848 	hostdata->targets_present = 0;
849 	hostdata->connected = NULL;
850 	hostdata->issue_queue = NULL;
851 	hostdata->disconnected_queue = NULL;
852 
853 	INIT_WORK(&hostdata->coroutine, NCR5380_main, hostdata);
854 
855 #ifdef NCR5380_STATS
856 	for (i = 0; i < 8; ++i) {
857 		hostdata->time_read[i] = 0;
858 		hostdata->time_write[i] = 0;
859 		hostdata->bytes_read[i] = 0;
860 		hostdata->bytes_write[i] = 0;
861 	}
862 	hostdata->timebase = 0;
863 	hostdata->pendingw = 0;
864 	hostdata->pendingr = 0;
865 #endif
866 
867 	/* The CHECK code seems to break the 53C400. Will check it later maybe */
868 	if (flags & FLAG_NCR53C400)
869 		hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
870 	else
871 		hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
872 
873 	hostdata->host = instance;
874 	hostdata->time_expires = 0;
875 
876 #ifndef AUTOSENSE
877 	if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
878 		    printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
879 		    	   "         be incorrectly cleared.\n", instance->host_no);
880 #endif				/* def AUTOSENSE */
881 
882 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
883 	NCR5380_write(MODE_REG, MR_BASE);
884 	NCR5380_write(TARGET_COMMAND_REG, 0);
885 	NCR5380_write(SELECT_ENABLE_REG, 0);
886 
887 #ifdef NCR53C400
888 	if (hostdata->flags & FLAG_NCR53C400) {
889 		NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
890 	}
891 #endif
892 
893 	/*
894 	 * Detect and correct bus wedge problems.
895 	 *
896 	 * If the system crashed, it may have crashed in a state
897 	 * where a SCSI command was still executing, and the
898 	 * SCSI bus is not in a BUS FREE STATE.
899 	 *
900 	 * If this is the case, we'll try to abort the currently
901 	 * established nexus which we know nothing about, and that
902 	 * failing, do a hard reset of the SCSI bus
903 	 */
904 
905 	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
906 		switch (pass) {
907 		case 1:
908 		case 3:
909 		case 5:
910 			printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
911 			timeout = jiffies + 5 * HZ;
912 			NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
913 			break;
914 		case 2:
915 			printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
916 			do_abort(instance);
917 			break;
918 		case 4:
919 			printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
920 			do_reset(instance);
921 			break;
922 		case 6:
923 			printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
924 			return -ENXIO;
925 		}
926 	}
927 	return 0;
928 }
929 
930 /**
931  *	NCR5380_exit	-	remove an NCR5380
932  *	@instance: adapter to remove
933  */
934 
935 static void __devexit NCR5380_exit(struct Scsi_Host *instance)
936 {
937 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
938 
939 	cancel_delayed_work(&hostdata->coroutine);
940 	flush_scheduled_work();
941 }
942 
943 /**
944  *	NCR5380_queue_command 		-	queue a command
945  *	@cmd: SCSI command
946  *	@done: completion handler
947  *
948  *      cmd is added to the per instance issue_queue, with minor
949  *      twiddling done to the host specific fields of cmd.  If the
950  *      main coroutine is not running, it is restarted.
951  *
952  *	Locks: host lock taken by caller
953  */
954 
955 static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
956 {
957 	struct Scsi_Host *instance = cmd->device->host;
958 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
959 	Scsi_Cmnd *tmp;
960 
961 #if (NDEBUG & NDEBUG_NO_WRITE)
962 	switch (cmd->cmnd[0]) {
963 	case WRITE_6:
964 	case WRITE_10:
965 		printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
966 		cmd->result = (DID_ERROR << 16);
967 		done(cmd);
968 		return 0;
969 	}
970 #endif				/* (NDEBUG & NDEBUG_NO_WRITE) */
971 
972 #ifdef NCR5380_STATS
973 	switch (cmd->cmnd[0]) {
974 		case WRITE:
975 		case WRITE_6:
976 		case WRITE_10:
977 			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
978 			hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
979 			hostdata->pendingw++;
980 			break;
981 		case READ:
982 		case READ_6:
983 		case READ_10:
984 			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
985 			hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
986 			hostdata->pendingr++;
987 			break;
988 	}
989 #endif
990 
991 	/*
992 	 * We use the host_scribble field as a pointer to the next command
993 	 * in a queue
994 	 */
995 
996 	cmd->host_scribble = NULL;
997 	cmd->scsi_done = done;
998 	cmd->result = 0;
999 
1000 	/*
1001 	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
1002 	 * commands are added to the head of the queue since any command will
1003 	 * clear the contingent allegiance condition that exists and the
1004 	 * sense data is only guaranteed to be valid while the condition exists.
1005 	 */
1006 
1007 	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1008 		LIST(cmd, hostdata->issue_queue);
1009 		cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1010 		hostdata->issue_queue = cmd;
1011 	} else {
1012 		for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1013 		LIST(cmd, tmp);
1014 		tmp->host_scribble = (unsigned char *) cmd;
1015 	}
1016 	dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1017 
1018 	/* Run the coroutine if it isn't already running. */
1019 	/* Kick off command processing */
1020 	schedule_work(&hostdata->coroutine);
1021 	return 0;
1022 }
1023 
1024 
1025 /**
1026  *	NCR5380_main	-	NCR state machines
1027  *
1028  *	NCR5380_main is a coroutine that runs as long as more work can
1029  *      be done on the NCR5380 host adapters in a system.  Both
1030  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1031  *      in case it is not running.
1032  *
1033  *	Locks: called as its own thread with no locks held. Takes the
1034  *	host lock and called routines may take the isa dma lock.
1035  */
1036 
1037 static void NCR5380_main(void *p)
1038 {
1039 	struct NCR5380_hostdata *hostdata = p;
1040 	struct Scsi_Host *instance = hostdata->host;
1041 	Scsi_Cmnd *tmp, *prev;
1042 	int done;
1043 
1044 	spin_lock_irq(instance->host_lock);
1045 	do {
1046 		/* Lock held here */
1047 		done = 1;
1048 		if (!hostdata->connected && !hostdata->selecting) {
1049 			dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1050 			/*
1051 			 * Search through the issue_queue for a command destined
1052 			 * for a target that's not busy.
1053 			 */
1054 			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
1055 			{
1056 				if (prev != tmp)
1057 					dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1058 				/*  When we find one, remove it from the issue queue. */
1059 				if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1060 					if (prev) {
1061 						REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1062 						prev->host_scribble = tmp->host_scribble;
1063 					} else {
1064 						REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1065 						hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1066 					}
1067 					tmp->host_scribble = NULL;
1068 
1069 					/*
1070 					 * Attempt to establish an I_T_L nexus here.
1071 					 * On success, instance->hostdata->connected is set.
1072 					 * On failure, we must add the command back to the
1073 					 *   issue queue so we can keep trying.
1074 					 */
1075 					dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->target, tmp->lun));
1076 
1077 					/*
1078 					 * A successful selection is defined as one that
1079 					 * leaves us with the command connected and
1080 					 * in hostdata->connected, OR has terminated the
1081 					 * command.
1082 					 *
1083 					 * With successful commands, we fall through
1084 					 * and see if we can do an information transfer,
1085 					 * with failures we will restart.
1086 					 */
1087 					hostdata->selecting = NULL;
1088 					/* RvC: have to preset this to indicate a new command is being performed */
1089 
1090 					if (!NCR5380_select(instance, tmp,
1091 							    /*
1092 							     * REQUEST SENSE commands are issued without tagged
1093 							     * queueing, even on SCSI-II devices because the
1094 							     * contingent allegiance condition exists for the
1095 							     * entire unit.
1096 							     */
1097 							    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1098 						break;
1099 					} else {
1100 						LIST(tmp, hostdata->issue_queue);
1101 						tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1102 						hostdata->issue_queue = tmp;
1103 						done = 0;
1104 						dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1105 					}
1106 					/* lock held here still */
1107 				}	/* if target/lun is not busy */
1108 			}	/* for */
1109 			/* exited locked */
1110 		}	/* if (!hostdata->connected) */
1111 		if (hostdata->selecting) {
1112 			tmp = (Scsi_Cmnd *) hostdata->selecting;
1113 			/* Selection will drop and retake the lock */
1114 			if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1115 				/* Ok ?? */
1116 			} else {
1117 				/* RvC: device failed, so we wait a long time
1118 				   this is needed for Mustek scanners, that
1119 				   do not respond to commands immediately
1120 				   after a scan */
1121 				printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1122 				LIST(tmp, hostdata->issue_queue);
1123 				tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1124 				hostdata->issue_queue = tmp;
1125 				NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1126 			}
1127 		}	/* if hostdata->selecting */
1128 		if (hostdata->connected
1129 #ifdef REAL_DMA
1130 		    && !hostdata->dmalen
1131 #endif
1132 		    && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1133 		    ) {
1134 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1135 			NCR5380_information_transfer(instance);
1136 			dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1137 			done = 0;
1138 		} else
1139 			break;
1140 	} while (!done);
1141 
1142 	spin_unlock_irq(instance->host_lock);
1143 }
1144 
1145 #ifndef DONT_USE_INTR
1146 
1147 /**
1148  * 	NCR5380_intr	-	generic NCR5380 irq handler
1149  *	@irq: interrupt number
1150  *	@dev_id: device info
1151  *	@regs: registers (unused)
1152  *
1153  *	Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1154  *      from the disconnected queue, and restarting NCR5380_main()
1155  *      as required.
1156  *
1157  *	Locks: takes the needed instance locks
1158  */
1159 
1160 static irqreturn_t NCR5380_intr(int irq, void *dev_id, struct pt_regs *regs)
1161 {
1162 	NCR5380_local_declare();
1163 	struct Scsi_Host *instance = (struct Scsi_Host *)dev_id;
1164 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1165 	int done;
1166 	unsigned char basr;
1167 	unsigned long flags;
1168 
1169 	dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
1170 
1171 	do {
1172 		done = 1;
1173 		spin_lock_irqsave(instance->host_lock, flags);
1174 		/* Look for pending interrupts */
1175 		NCR5380_setup(instance);
1176 		basr = NCR5380_read(BUS_AND_STATUS_REG);
1177 		/* XXX dispatch to appropriate routine if found and done=0 */
1178 		if (basr & BASR_IRQ) {
1179 			NCR5380_dprint(NDEBUG_INTR, instance);
1180 			if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1181 				done = 0;
1182 				dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1183 				NCR5380_reselect(instance);
1184 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1185 			} else if (basr & BASR_PARITY_ERROR) {
1186 				dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1187 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1188 			} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1189 				dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1190 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1191 			} else {
1192 #if defined(REAL_DMA)
1193 				/*
1194 				 * We should only get PHASE MISMATCH and EOP interrupts
1195 				 * if we have DMA enabled, so do a sanity check based on
1196 				 * the current setting of the MODE register.
1197 				 */
1198 
1199 				if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1200 					int transfered;
1201 
1202 					if (!hostdata->connected)
1203 						panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1204 
1205 					transfered = (hostdata->dmalen - NCR5380_dma_residual(instance));
1206 					hostdata->connected->SCp.this_residual -= transferred;
1207 					hostdata->connected->SCp.ptr += transferred;
1208 					hostdata->dmalen = 0;
1209 
1210 					(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1211 
1212 					/* FIXME: we need to poll briefly then defer a workqueue task ! */
1213 					NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1214 
1215 					NCR5380_write(MODE_REG, MR_BASE);
1216 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1217 				}
1218 #else
1219 				dprintk(NDEBUG_INTR, ("scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)));
1220 				(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1221 #endif
1222 			}
1223 		}	/* if BASR_IRQ */
1224 		spin_unlock_irqrestore(instance->host_lock, flags);
1225 		if(!done)
1226 			schedule_work(&hostdata->coroutine);
1227 	} while (!done);
1228 	return IRQ_HANDLED;
1229 }
1230 
1231 #endif
1232 
1233 /**
1234  *	collect_stats		-	collect stats on a scsi command
1235  *	@hostdata: adapter
1236  *	@cmd: command being issued
1237  *
1238  *	Update the statistical data by parsing the command in question
1239  */
1240 
1241 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd)
1242 {
1243 #ifdef NCR5380_STATS
1244 	switch (cmd->cmnd[0]) {
1245 	case WRITE:
1246 	case WRITE_6:
1247 	case WRITE_10:
1248 		hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1249 		hostdata->pendingw--;
1250 		break;
1251 	case READ:
1252 	case READ_6:
1253 	case READ_10:
1254 		hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1255 		hostdata->pendingr--;
1256 		break;
1257 	}
1258 #endif
1259 }
1260 
1261 
1262 /*
1263  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1264  *      int tag);
1265  *
1266  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1267  *      including ARBITRATION, SELECTION, and initial message out for
1268  *      IDENTIFY and queue messages.
1269  *
1270  * Inputs : instance - instantiation of the 5380 driver on which this
1271  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1272  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1273  *      the command that is presently connected.
1274  *
1275  * Returns : -1 if selection could not execute for some reason,
1276  *      0 if selection succeeded or failed because the target
1277  *      did not respond.
1278  *
1279  * Side effects :
1280  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1281  *              with registers as they should have been on entry - ie
1282  *              SELECT_ENABLE will be set appropriately, the NCR5380
1283  *              will cease to drive any SCSI bus signals.
1284  *
1285  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1286  *              instance->connected will be set to cmd.
1287  *              SELECT interrupt will be disabled.
1288  *
1289  *      If failed (no target) : cmd->scsi_done() will be called, and the
1290  *              cmd->result host byte set to DID_BAD_TARGET.
1291  *
1292  *	Locks: caller holds hostdata lock in IRQ mode
1293  */
1294 
1295 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag)
1296 {
1297 	NCR5380_local_declare();
1298 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1299 	unsigned char tmp[3], phase;
1300 	unsigned char *data;
1301 	int len;
1302 	unsigned long timeout;
1303 	unsigned char value;
1304 	int err;
1305 	NCR5380_setup(instance);
1306 
1307 	if (hostdata->selecting)
1308 		goto part2;
1309 
1310 	hostdata->restart_select = 0;
1311 
1312 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1313 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1314 
1315 	/*
1316 	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1317 	 * data bus during SELECTION.
1318 	 */
1319 
1320 	NCR5380_write(TARGET_COMMAND_REG, 0);
1321 
1322 	/*
1323 	 * Start arbitration.
1324 	 */
1325 
1326 	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1327 	NCR5380_write(MODE_REG, MR_ARBITRATE);
1328 
1329 
1330 	/* We can be relaxed here, interrupts are on, we are
1331 	   in workqueue context, the birds are singing in the trees */
1332 	spin_unlock_irq(instance->host_lock);
1333 	err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1334 	spin_lock_irq(instance->host_lock);
1335 	if (err < 0) {
1336 		printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1337 		NCR5380_write(MODE_REG, MR_BASE);
1338 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1339 		goto failed;
1340 	}
1341 
1342 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1343 
1344 	/*
1345 	 * The arbitration delay is 2.2us, but this is a minimum and there is
1346 	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1347 	 * the integral nature of udelay().
1348 	 *
1349 	 */
1350 
1351 	udelay(3);
1352 
1353 	/* Check for lost arbitration */
1354 	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1355 		NCR5380_write(MODE_REG, MR_BASE);
1356 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1357 		goto failed;
1358 	}
1359 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1360 
1361 	if (!(hostdata->flags & FLAG_DTC3181E) &&
1362 	    /* RvC: DTC3181E has some trouble with this
1363 	     *      so we simply removed it. Seems to work with
1364 	     *      only Mustek scanner attached
1365 	     */
1366 	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1367 		NCR5380_write(MODE_REG, MR_BASE);
1368 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1369 		dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1370 		goto failed;
1371 	}
1372 	/*
1373 	 * Again, bus clear + bus settle time is 1.2us, however, this is
1374 	 * a minimum so we'll udelay ceil(1.2)
1375 	 */
1376 
1377 	udelay(2);
1378 
1379 	dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1380 
1381 	/*
1382 	 * Now that we have won arbitration, start Selection process, asserting
1383 	 * the host and target ID's on the SCSI bus.
1384 	 */
1385 
1386 	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1387 
1388 	/*
1389 	 * Raise ATN while SEL is true before BSY goes false from arbitration,
1390 	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1391 	 * phase immediately after selection.
1392 	 */
1393 
1394 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1395 	NCR5380_write(MODE_REG, MR_BASE);
1396 
1397 	/*
1398 	 * Reselect interrupts must be turned off prior to the dropping of BSY,
1399 	 * otherwise we will trigger an interrupt.
1400 	 */
1401 	NCR5380_write(SELECT_ENABLE_REG, 0);
1402 
1403 	/*
1404 	 * The initiator shall then wait at least two deskew delays and release
1405 	 * the BSY signal.
1406 	 */
1407 	udelay(1);		/* wingel -- wait two bus deskew delay >2*45ns */
1408 
1409 	/* Reset BSY */
1410 	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1411 
1412 	/*
1413 	 * Something weird happens when we cease to drive BSY - looks
1414 	 * like the board/chip is letting us do another read before the
1415 	 * appropriate propagation delay has expired, and we're confusing
1416 	 * a BSY signal from ourselves as the target's response to SELECTION.
1417 	 *
1418 	 * A small delay (the 'C++' frontend breaks the pipeline with an
1419 	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1420 	 * tighter 'C' code breaks and requires this) solves the problem -
1421 	 * the 1 us delay is arbitrary, and only used because this delay will
1422 	 * be the same on other platforms and since it works here, it should
1423 	 * work there.
1424 	 *
1425 	 * wingel suggests that this could be due to failing to wait
1426 	 * one deskew delay.
1427 	 */
1428 
1429 	udelay(1);
1430 
1431 	dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1432 
1433 	/*
1434 	 * The SCSI specification calls for a 250 ms timeout for the actual
1435 	 * selection.
1436 	 */
1437 
1438 	timeout = jiffies + (250 * HZ / 1000);
1439 
1440 	/*
1441 	 * XXX very interesting - we're seeing a bounce where the BSY we
1442 	 * asserted is being reflected / still asserted (propagation delay?)
1443 	 * and it's detecting as true.  Sigh.
1444 	 */
1445 
1446 	hostdata->select_time = 0;	/* we count the clock ticks at which we polled */
1447 	hostdata->selecting = cmd;
1448 
1449 part2:
1450 	/* RvC: here we enter after a sleeping period, or immediately after
1451 	   execution of part 1
1452 	   we poll only once ech clock tick */
1453 	value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1454 
1455 	if (!value && (hostdata->select_time < HZ/4)) {
1456 		/* RvC: we still must wait for a device response */
1457 		hostdata->select_time++;	/* after 25 ticks the device has failed */
1458 		NCR5380_set_timer(hostdata, 1);
1459 		return 0;	/* RvC: we return here with hostdata->selecting set,
1460 				   to go to sleep */
1461 	}
1462 
1463 	hostdata->selecting = NULL;/* clear this pointer, because we passed the
1464 					   waiting period */
1465 	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1466 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1467 		NCR5380_reselect(instance);
1468 		printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1469 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1470 		return -1;
1471 	}
1472 	/*
1473 	 * No less than two deskew delays after the initiator detects the
1474 	 * BSY signal is true, it shall release the SEL signal and may
1475 	 * change the DATA BUS.                                     -wingel
1476 	 */
1477 
1478 	udelay(1);
1479 
1480 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1481 
1482 	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1483 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1484 		if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1485 			printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1486 			if (hostdata->restart_select)
1487 				printk(KERN_DEBUG "\trestart select\n");
1488 			NCR5380_dprint(NDEBUG_SELECTION, instance);
1489 			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1490 			return -1;
1491 		}
1492 		cmd->result = DID_BAD_TARGET << 16;
1493 		collect_stats(hostdata, cmd);
1494 		cmd->scsi_done(cmd);
1495 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1496 		dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1497 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1498 		return 0;
1499 	}
1500 	hostdata->targets_present |= (1 << scmd_id(cmd));
1501 
1502 	/*
1503 	 * Since we followed the SCSI spec, and raised ATN while SEL
1504 	 * was true but before BSY was false during selection, the information
1505 	 * transfer phase should be a MESSAGE OUT phase so that we can send the
1506 	 * IDENTIFY message.
1507 	 *
1508 	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1509 	 * message (2 bytes) with a tag ID that we increment with every command
1510 	 * until it wraps back to 0.
1511 	 *
1512 	 * XXX - it turns out that there are some broken SCSI-II devices,
1513 	 *       which claim to support tagged queuing but fail when more than
1514 	 *       some number of commands are issued at once.
1515 	 */
1516 
1517 	/* Wait for start of REQ/ACK handshake */
1518 
1519 	spin_unlock_irq(instance->host_lock);
1520 	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1521 	spin_lock_irq(instance->host_lock);
1522 
1523 	if(err) {
1524 		printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1525 		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1526 		goto failed;
1527 	}
1528 
1529 	dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1530 	tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1531 
1532 	len = 1;
1533 	cmd->tag = 0;
1534 
1535 	/* Send message(s) */
1536 	data = tmp;
1537 	phase = PHASE_MSGOUT;
1538 	NCR5380_transfer_pio(instance, &phase, &len, &data);
1539 	dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1540 	/* XXX need to handle errors here */
1541 	hostdata->connected = cmd;
1542 	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1543 
1544 	if (cmd->SCp.ptr != (char *)cmd->sense_buffer) {
1545 		initialize_SCp(cmd);
1546 	}
1547 
1548 	return 0;
1549 
1550 	/* Selection failed */
1551 failed:
1552 	return -1;
1553 
1554 }
1555 
1556 /*
1557  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1558  *      unsigned char *phase, int *count, unsigned char **data)
1559  *
1560  * Purpose : transfers data in given phase using polled I/O
1561  *
1562  * Inputs : instance - instance of driver, *phase - pointer to
1563  *      what phase is expected, *count - pointer to number of
1564  *      bytes to transfer, **data - pointer to data pointer.
1565  *
1566  * Returns : -1 when different phase is entered without transferring
1567  *      maximum number of bytes, 0 if all bytes or transfered or exit
1568  *      is in same phase.
1569  *
1570  *      Also, *phase, *count, *data are modified in place.
1571  *
1572  * XXX Note : handling for bus free may be useful.
1573  */
1574 
1575 /*
1576  * Note : this code is not as quick as it could be, however it
1577  * IS 100% reliable, and for the actual data transfer where speed
1578  * counts, we will always do a pseudo DMA or DMA transfer.
1579  */
1580 
1581 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1582 	NCR5380_local_declare();
1583 	unsigned char p = *phase, tmp;
1584 	int c = *count;
1585 	unsigned char *d = *data;
1586 	/*
1587 	 *      RvC: some administrative data to process polling time
1588 	 */
1589 	int break_allowed = 0;
1590 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1591 	NCR5380_setup(instance);
1592 
1593 	if (!(p & SR_IO))
1594 		dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1595 	else
1596 		dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1597 
1598 	/*
1599 	 * The NCR5380 chip will only drive the SCSI bus when the
1600 	 * phase specified in the appropriate bits of the TARGET COMMAND
1601 	 * REGISTER match the STATUS REGISTER
1602 	 */
1603 
1604 	 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1605 
1606 	/* RvC: don't know if this is necessary, but other SCSI I/O is short
1607 	 *      so breaks are not necessary there
1608 	 */
1609 	if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1610 		break_allowed = 1;
1611 	}
1612 	do {
1613 		/*
1614 		 * Wait for assertion of REQ, after which the phase bits will be
1615 		 * valid
1616 		 */
1617 
1618 		/* RvC: we simply poll once, after that we stop temporarily
1619 		 *      and let the device buffer fill up
1620 		 *      if breaking is not allowed, we keep polling as long as needed
1621 		 */
1622 
1623 		/* FIXME */
1624 		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1625 		if (!(tmp & SR_REQ)) {
1626 			/* timeout condition */
1627 			NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1628 			break;
1629 		}
1630 
1631 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1632 
1633 		/* Check for phase mismatch */
1634 		if ((tmp & PHASE_MASK) != p) {
1635 			dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1636 			NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1637 			break;
1638 		}
1639 		/* Do actual transfer from SCSI bus to / from memory */
1640 		if (!(p & SR_IO))
1641 			NCR5380_write(OUTPUT_DATA_REG, *d);
1642 		else
1643 			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1644 
1645 		++d;
1646 
1647 		/*
1648 		 * The SCSI standard suggests that in MSGOUT phase, the initiator
1649 		 * should drop ATN on the last byte of the message phase
1650 		 * after REQ has been asserted for the handshake but before
1651 		 * the initiator raises ACK.
1652 		 */
1653 
1654 		if (!(p & SR_IO)) {
1655 			if (!((p & SR_MSG) && c > 1)) {
1656 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1657 				NCR5380_dprint(NDEBUG_PIO, instance);
1658 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1659 			} else {
1660 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1661 				NCR5380_dprint(NDEBUG_PIO, instance);
1662 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1663 			}
1664 		} else {
1665 			NCR5380_dprint(NDEBUG_PIO, instance);
1666 			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1667 		}
1668 
1669 		/* FIXME - if this fails bus reset ?? */
1670 		NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1671 		dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1672 
1673 /*
1674  * We have several special cases to consider during REQ/ACK handshaking :
1675  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1676  *      message.  ATN must be dropped as ACK is dropped.
1677  *
1678  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1679  *      message.  We must exit with ACK asserted, so that the calling
1680  *      code may raise ATN before dropping ACK to reject the message.
1681  *
1682  * 3.  ACK and ATN are clear and the target may proceed as normal.
1683  */
1684 		if (!(p == PHASE_MSGIN && c == 1)) {
1685 			if (p == PHASE_MSGOUT && c > 1)
1686 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1687 			else
1688 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1689 		}
1690 	} while (--c);
1691 
1692 	dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1693 
1694 	*count = c;
1695 	*data = d;
1696 	tmp = NCR5380_read(STATUS_REG);
1697 	if (tmp & SR_REQ)
1698 		*phase = tmp & PHASE_MASK;
1699 	else
1700 		*phase = PHASE_UNKNOWN;
1701 
1702 	if (!c || (*phase == p))
1703 		return 0;
1704 	else
1705 		return -1;
1706 }
1707 
1708 /**
1709  *	do_reset	-	issue a reset command
1710  *	@host: adapter to reset
1711  *
1712  *	Issue a reset sequence to the NCR5380 and try and get the bus
1713  *	back into sane shape.
1714  *
1715  *	Locks: caller holds queue lock
1716  */
1717 
1718 static void do_reset(struct Scsi_Host *host) {
1719 	NCR5380_local_declare();
1720 	NCR5380_setup(host);
1721 
1722 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1723 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1724 	udelay(25);
1725 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1726 }
1727 
1728 /*
1729  * Function : do_abort (Scsi_Host *host)
1730  *
1731  * Purpose : abort the currently established nexus.  Should only be
1732  *      called from a routine which can drop into a
1733  *
1734  * Returns : 0 on success, -1 on failure.
1735  *
1736  * Locks: queue lock held by caller
1737  *	FIXME: sort this out and get new_eh running
1738  */
1739 
1740 static int do_abort(struct Scsi_Host *host) {
1741 	NCR5380_local_declare();
1742 	unsigned char *msgptr, phase, tmp;
1743 	int len;
1744 	int rc;
1745 	NCR5380_setup(host);
1746 
1747 
1748 	/* Request message out phase */
1749 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1750 
1751 	/*
1752 	 * Wait for the target to indicate a valid phase by asserting
1753 	 * REQ.  Once this happens, we'll have either a MSGOUT phase
1754 	 * and can immediately send the ABORT message, or we'll have some
1755 	 * other phase and will have to source/sink data.
1756 	 *
1757 	 * We really don't care what value was on the bus or what value
1758 	 * the target sees, so we just handshake.
1759 	 */
1760 
1761 	rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1762 
1763 	if(rc < 0)
1764 		return -1;
1765 
1766 	tmp = (unsigned char)rc;
1767 
1768 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1769 
1770 	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1771 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1772 		rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1773 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1774 		if(rc == -1)
1775 			return -1;
1776 	}
1777 	tmp = ABORT;
1778 	msgptr = &tmp;
1779 	len = 1;
1780 	phase = PHASE_MSGOUT;
1781 	NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1782 
1783 	/*
1784 	 * If we got here, and the command completed successfully,
1785 	 * we're about to go into bus free state.
1786 	 */
1787 
1788 	return len ? -1 : 0;
1789 }
1790 
1791 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1792 /*
1793  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1794  *      unsigned char *phase, int *count, unsigned char **data)
1795  *
1796  * Purpose : transfers data in given phase using either real
1797  *      or pseudo DMA.
1798  *
1799  * Inputs : instance - instance of driver, *phase - pointer to
1800  *      what phase is expected, *count - pointer to number of
1801  *      bytes to transfer, **data - pointer to data pointer.
1802  *
1803  * Returns : -1 when different phase is entered without transferring
1804  *      maximum number of bytes, 0 if all bytes or transfered or exit
1805  *      is in same phase.
1806  *
1807  *      Also, *phase, *count, *data are modified in place.
1808  *
1809  *	Locks: io_request lock held by caller
1810  */
1811 
1812 
1813 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1814 	NCR5380_local_declare();
1815 	register int c = *count;
1816 	register unsigned char p = *phase;
1817 	register unsigned char *d = *data;
1818 	unsigned char tmp;
1819 	int foo;
1820 #if defined(REAL_DMA_POLL)
1821 	int cnt, toPIO;
1822 	unsigned char saved_data = 0, overrun = 0, residue;
1823 #endif
1824 
1825 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1826 
1827 	NCR5380_setup(instance);
1828 
1829 	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1830 		*phase = tmp;
1831 		return -1;
1832 	}
1833 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1834 #ifdef READ_OVERRUNS
1835 	if (p & SR_IO) {
1836 		c -= 2;
1837 	}
1838 #endif
1839 	dprintk(NDEBUG_DMA, ("scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d));
1840 	hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1841 #endif
1842 
1843 	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1844 
1845 #ifdef REAL_DMA
1846 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1847 #elif defined(REAL_DMA_POLL)
1848 	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1849 #else
1850 	/*
1851 	 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1852 	 * were not disabled for the duration of a single DMA transfer, from
1853 	 * before the setting of DMA mode to after transfer of the last byte.
1854 	 */
1855 
1856 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1857 	spin_unlock_irq(instance->host_lock);
1858 #endif
1859 	/* KLL May need eop and parity in 53c400 */
1860 	if (hostdata->flags & FLAG_NCR53C400)
1861 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR | MR_ENABLE_EOP_INTR | MR_DMA_MODE | MR_MONITOR_BSY);
1862 	else
1863 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1864 #endif				/* def REAL_DMA */
1865 
1866 	dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1867 
1868 	/*
1869 	 *	On the PAS16 at least I/O recovery delays are not needed here.
1870 	 *	Everyone else seems to want them.
1871 	 */
1872 
1873 	if (p & SR_IO) {
1874 		io_recovery_delay(1);
1875 		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1876 	} else {
1877 		io_recovery_delay(1);
1878 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1879 		io_recovery_delay(1);
1880 		NCR5380_write(START_DMA_SEND_REG, 0);
1881 		io_recovery_delay(1);
1882 	}
1883 
1884 #if defined(REAL_DMA_POLL)
1885 	do {
1886 		tmp = NCR5380_read(BUS_AND_STATUS_REG);
1887 	} while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1888 
1889 /*
1890    At this point, either we've completed DMA, or we have a phase mismatch,
1891    or we've unexpectedly lost BUSY (which is a real error).
1892 
1893    For write DMAs, we want to wait until the last byte has been
1894    transferred out over the bus before we turn off DMA mode.  Alas, there
1895    seems to be no terribly good way of doing this on a 5380 under all
1896    conditions.  For non-scatter-gather operations, we can wait until REQ
1897    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1898    are nastier, since the device will be expecting more data than we
1899    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1900    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1901    why this signal was added to the newer chips) but on the older 538[01]
1902    this signal does not exist.  The workaround for this lack is a watchdog;
1903    we bail out of the wait-loop after a modest amount of wait-time if
1904    the usual exit conditions are not met.  Not a terribly clean or
1905    correct solution :-%
1906 
1907    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1908    If the chip is in DMA mode for an READ, it will respond to a target's
1909    REQ by latching the SCSI data into the INPUT DATA register and asserting
1910    ACK, even if it has _already_ been notified by the DMA controller that
1911    the current DMA transfer has completed!  If the NCR5380 is then taken
1912    out of DMA mode, this already-acknowledged byte is lost.
1913 
1914    This is not a problem for "one DMA transfer per command" reads, because
1915    the situation will never arise... either all of the data is DMA'ed
1916    properly, or the target switches to MESSAGE IN phase to signal a
1917    disconnection (either operation bringing the DMA to a clean halt).
1918    However, in order to handle scatter-reads, we must work around the
1919    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1920    condition before taking the NCR5380 out of DMA mode.  One or two extra
1921    bytes are transferred via PIO as necessary to fill out the original
1922    request.
1923  */
1924 
1925 	if (p & SR_IO) {
1926 #ifdef READ_OVERRUNS
1927 		udelay(10);
1928 		if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1929 			saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1930 			overrun = 1;
1931 		}
1932 #endif
1933 	} else {
1934 		int limit = 100;
1935 		while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1936 			if (!(tmp & BASR_PHASE_MATCH))
1937 				break;
1938 			if (--limit < 0)
1939 				break;
1940 		}
1941 	}
1942 
1943 	dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1944 
1945 	NCR5380_write(MODE_REG, MR_BASE);
1946 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1947 
1948 	residue = NCR5380_dma_residual(instance);
1949 	c -= residue;
1950 	*count -= c;
1951 	*data += c;
1952 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1953 
1954 #ifdef READ_OVERRUNS
1955 	if (*phase == p && (p & SR_IO) && residue == 0) {
1956 		if (overrun) {
1957 			dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1958 			**data = saved_data;
1959 			*data += 1;
1960 			*count -= 1;
1961 			cnt = toPIO = 1;
1962 		} else {
1963 			printk("No overrun??\n");
1964 			cnt = toPIO = 2;
1965 		}
1966 		dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1967 		NCR5380_transfer_pio(instance, phase, &cnt, data);
1968 		*count -= toPIO - cnt;
1969 	}
1970 #endif
1971 
1972 	dprintk(NDEBUG_DMA, ("Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count)));
1973 	return 0;
1974 
1975 #elif defined(REAL_DMA)
1976 	return 0;
1977 #else				/* defined(REAL_DMA_POLL) */
1978 	if (p & SR_IO) {
1979 #ifdef DMA_WORKS_RIGHT
1980 		foo = NCR5380_pread(instance, d, c);
1981 #else
1982 		int diff = 1;
1983 		if (hostdata->flags & FLAG_NCR53C400) {
1984 			diff = 0;
1985 		}
1986 		if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1987 			/*
1988 			 * We can't disable DMA mode after successfully transferring
1989 			 * what we plan to be the last byte, since that would open up
1990 			 * a race condition where if the target asserted REQ before
1991 			 * we got the DMA mode reset, the NCR5380 would have latched
1992 			 * an additional byte into the INPUT DATA register and we'd
1993 			 * have dropped it.
1994 			 *
1995 			 * The workaround was to transfer one fewer bytes than we
1996 			 * intended to with the pseudo-DMA read function, wait for
1997 			 * the chip to latch the last byte, read it, and then disable
1998 			 * pseudo-DMA mode.
1999 			 *
2000 			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
2001 			 * REQ is deasserted when ACK is asserted, and not reasserted
2002 			 * until ACK goes false.  Since the NCR5380 won't lower ACK
2003 			 * until DACK is asserted, which won't happen unless we twiddle
2004 			 * the DMA port or we take the NCR5380 out of DMA mode, we
2005 			 * can guarantee that we won't handshake another extra
2006 			 * byte.
2007 			 */
2008 
2009 			if (!(hostdata->flags & FLAG_NCR53C400)) {
2010 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2011 				/* Wait for clean handshake */
2012 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2013 				d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2014 			}
2015 		}
2016 #endif
2017 	} else {
2018 #ifdef DMA_WORKS_RIGHT
2019 		foo = NCR5380_pwrite(instance, d, c);
2020 #else
2021 		int timeout;
2022 		dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2023 		if (!(foo = NCR5380_pwrite(instance, d, c))) {
2024 			/*
2025 			 * Wait for the last byte to be sent.  If REQ is being asserted for
2026 			 * the byte we're interested, we'll ACK it and it will go false.
2027 			 */
2028 			if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2029 				timeout = 20000;
2030 				while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2031 
2032 				if (!timeout)
2033 					dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2034 
2035 				if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2036 					hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2037 					if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2038 						hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2039 						dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2040 					}
2041 				}
2042 			} else {
2043 				dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2044 				while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2045 				dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2046 			}
2047 		}
2048 #endif
2049 	}
2050 	NCR5380_write(MODE_REG, MR_BASE);
2051 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2052 
2053 	if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2054 		dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2055 		if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2056 			dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2057 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2058 		} else {
2059 			printk("53C400w:    IRQ NOT THERE!\n");
2060 		}
2061 	}
2062 	*data = d + c;
2063 	*count = 0;
2064 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2065 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2066 	spin_lock_irq(instance->host_lock);
2067 #endif				/* defined(REAL_DMA_POLL) */
2068 	return foo;
2069 #endif				/* def REAL_DMA */
2070 }
2071 #endif				/* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2072 
2073 /*
2074  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2075  *
2076  * Purpose : run through the various SCSI phases and do as the target
2077  *      directs us to.  Operates on the currently connected command,
2078  *      instance->connected.
2079  *
2080  * Inputs : instance, instance for which we are doing commands
2081  *
2082  * Side effects : SCSI things happen, the disconnected queue will be
2083  *      modified if a command disconnects, *instance->connected will
2084  *      change.
2085  *
2086  * XXX Note : we need to watch for bus free or a reset condition here
2087  *      to recover from an unexpected bus free condition.
2088  *
2089  * Locks: io_request_lock held by caller in IRQ mode
2090  */
2091 
2092 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2093 	NCR5380_local_declare();
2094 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2095 	unsigned char msgout = NOP;
2096 	int sink = 0;
2097 	int len;
2098 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2099 	int transfersize;
2100 #endif
2101 	unsigned char *data;
2102 	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2103 	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2104 	/* RvC: we need to set the end of the polling time */
2105 	unsigned long poll_time = jiffies + USLEEP_POLL;
2106 
2107 	NCR5380_setup(instance);
2108 
2109 	while (1) {
2110 		tmp = NCR5380_read(STATUS_REG);
2111 		/* We only have a valid SCSI phase when REQ is asserted */
2112 		if (tmp & SR_REQ) {
2113 			phase = (tmp & PHASE_MASK);
2114 			if (phase != old_phase) {
2115 				old_phase = phase;
2116 				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2117 			}
2118 			if (sink && (phase != PHASE_MSGOUT)) {
2119 				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2120 
2121 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2122 				while (NCR5380_read(STATUS_REG) & SR_REQ);
2123 				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2124 				sink = 0;
2125 				continue;
2126 			}
2127 			switch (phase) {
2128 			case PHASE_DATAIN:
2129 			case PHASE_DATAOUT:
2130 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2131 				printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2132 				sink = 1;
2133 				do_abort(instance);
2134 				cmd->result = DID_ERROR << 16;
2135 				cmd->done(cmd);
2136 				return;
2137 #endif
2138 				/*
2139 				 * If there is no room left in the current buffer in the
2140 				 * scatter-gather list, move onto the next one.
2141 				 */
2142 
2143 				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2144 					++cmd->SCp.buffer;
2145 					--cmd->SCp.buffers_residual;
2146 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
2147 					cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
2148 						       cmd->SCp.buffer->offset;
2149 					dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2150 				}
2151 				/*
2152 				 * The preferred transfer method is going to be
2153 				 * PSEUDO-DMA for systems that are strictly PIO,
2154 				 * since we can let the hardware do the handshaking.
2155 				 *
2156 				 * For this to work, we need to know the transfersize
2157 				 * ahead of time, since the pseudo-DMA code will sit
2158 				 * in an unconditional loop.
2159 				 */
2160 
2161 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2162 				/* KLL
2163 				 * PSEUDO_DMA is defined here. If this is the g_NCR5380
2164 				 * driver then it will always be defined, so the
2165 				 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2166 				 * NCR5380 case.  I think this is a fairly clean solution.
2167 				 * We supplement these 2 if's with the flag.
2168 				 */
2169 #ifdef NCR5380_dma_xfer_len
2170 				if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2171 #else
2172 				transfersize = cmd->transfersize;
2173 
2174 #ifdef LIMIT_TRANSFERSIZE	/* If we have problems with interrupt service */
2175 				if (transfersize > 512)
2176 					transfersize = 512;
2177 #endif				/* LIMIT_TRANSFERSIZE */
2178 
2179 				if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2180 					/* Limit transfers to 32K, for xx400 & xx406
2181 					 * pseudoDMA that transfers in 128 bytes blocks. */
2182 					if (transfersize > 32 * 1024)
2183 						transfersize = 32 * 1024;
2184 #endif
2185 					len = transfersize;
2186 					if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2187 						/*
2188 						 * If the watchdog timer fires, all future accesses to this
2189 						 * device will use the polled-IO.
2190 						 */
2191 						scmd_printk(KERN_INFO, cmd,
2192 							    "switching to slow handshake\n");
2193 						cmd->device->borken = 1;
2194 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2195 						sink = 1;
2196 						do_abort(instance);
2197 						cmd->result = DID_ERROR << 16;
2198 						cmd->done(cmd);
2199 						/* XXX - need to source or sink data here, as appropriate */
2200 					} else
2201 						cmd->SCp.this_residual -= transfersize - len;
2202 				} else
2203 #endif				/* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2204 					NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2205 							     &cmd->SCp.ptr);
2206 				break;
2207 			case PHASE_MSGIN:
2208 				len = 1;
2209 				data = &tmp;
2210 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2211 				cmd->SCp.Message = tmp;
2212 
2213 				switch (tmp) {
2214 					/*
2215 					 * Linking lets us reduce the time required to get the
2216 					 * next command out to the device, hopefully this will
2217 					 * mean we don't waste another revolution due to the delays
2218 					 * required by ARBITRATION and another SELECTION.
2219 					 *
2220 					 * In the current implementation proposal, low level drivers
2221 					 * merely have to start the next command, pointed to by
2222 					 * next_link, done() is called as with unlinked commands.
2223 					 */
2224 #ifdef LINKED
2225 				case LINKED_CMD_COMPLETE:
2226 				case LINKED_FLG_CMD_COMPLETE:
2227 					/* Accept message by clearing ACK */
2228 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2229 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2230 					/*
2231 					 * Sanity check : A linked command should only terminate with
2232 					 * one of these messages if there are more linked commands
2233 					 * available.
2234 					 */
2235 					if (!cmd->next_link) {
2236 						printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2237 						sink = 1;
2238 						do_abort(instance);
2239 						return;
2240 					}
2241 					initialize_SCp(cmd->next_link);
2242 					/* The next command is still part of this process */
2243 					cmd->next_link->tag = cmd->tag;
2244 					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2245 					dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked request done, calling scsi_done().\n", instance->host_no, cmd->device->id, cmd->device->lun));
2246 					collect_stats(hostdata, cmd);
2247 					cmd->scsi_done(cmd);
2248 					cmd = hostdata->connected;
2249 					break;
2250 #endif				/* def LINKED */
2251 				case ABORT:
2252 				case COMMAND_COMPLETE:
2253 					/* Accept message by clearing ACK */
2254 					sink = 1;
2255 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2256 					hostdata->connected = NULL;
2257 					dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2258 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2259 
2260 					/*
2261 					 * I'm not sure what the correct thing to do here is :
2262 					 *
2263 					 * If the command that just executed is NOT a request
2264 					 * sense, the obvious thing to do is to set the result
2265 					 * code to the values of the stored parameters.
2266 					 *
2267 					 * If it was a REQUEST SENSE command, we need some way
2268 					 * to differentiate between the failure code of the original
2269 					 * and the failure code of the REQUEST sense - the obvious
2270 					 * case is success, where we fall through and leave the result
2271 					 * code unchanged.
2272 					 *
2273 					 * The non-obvious place is where the REQUEST SENSE failed
2274 					 */
2275 
2276 					if (cmd->cmnd[0] != REQUEST_SENSE)
2277 						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2278 					else if (status_byte(cmd->SCp.Status) != GOOD)
2279 						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2280 
2281 #ifdef AUTOSENSE
2282 					if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2283 						dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2284 						cmd->cmnd[0] = REQUEST_SENSE;
2285 						cmd->cmnd[1] &= 0xe0;
2286 						cmd->cmnd[2] = 0;
2287 						cmd->cmnd[3] = 0;
2288 						cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2289 						cmd->cmnd[5] = 0;
2290 
2291 						cmd->SCp.buffer = NULL;
2292 						cmd->SCp.buffers_residual = 0;
2293 						cmd->SCp.ptr = (char *) cmd->sense_buffer;
2294 						cmd->SCp.this_residual = sizeof(cmd->sense_buffer);
2295 
2296 						LIST(cmd, hostdata->issue_queue);
2297 						cmd->host_scribble = (unsigned char *)
2298 						    hostdata->issue_queue;
2299 						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2300 						dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2301 					} else
2302 #endif				/* def AUTOSENSE */
2303 					{
2304 						collect_stats(hostdata, cmd);
2305 						cmd->scsi_done(cmd);
2306 					}
2307 
2308 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2309 					/*
2310 					 * Restore phase bits to 0 so an interrupted selection,
2311 					 * arbitration can resume.
2312 					 */
2313 					NCR5380_write(TARGET_COMMAND_REG, 0);
2314 
2315 					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2316 						barrier();
2317 					return;
2318 				case MESSAGE_REJECT:
2319 					/* Accept message by clearing ACK */
2320 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2321 					switch (hostdata->last_message) {
2322 					case HEAD_OF_QUEUE_TAG:
2323 					case ORDERED_QUEUE_TAG:
2324 					case SIMPLE_QUEUE_TAG:
2325 						cmd->device->simple_tags = 0;
2326 						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2327 						break;
2328 					default:
2329 						break;
2330 					}
2331 				case DISCONNECT:{
2332 						/* Accept message by clearing ACK */
2333 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2334 						cmd->device->disconnect = 1;
2335 						LIST(cmd, hostdata->disconnected_queue);
2336 						cmd->host_scribble = (unsigned char *)
2337 						    hostdata->disconnected_queue;
2338 						hostdata->connected = NULL;
2339 						hostdata->disconnected_queue = cmd;
2340 						dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d lun %d was moved from connected to" "  the disconnected_queue\n", instance->host_no, cmd->device->id, cmd->device->lun));
2341 						/*
2342 						 * Restore phase bits to 0 so an interrupted selection,
2343 						 * arbitration can resume.
2344 						 */
2345 						NCR5380_write(TARGET_COMMAND_REG, 0);
2346 
2347 						/* Enable reselect interrupts */
2348 						NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2349 						/* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2350 						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2351 						while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2352 							barrier();
2353 						return;
2354 					}
2355 					/*
2356 					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2357 					 * operation, in violation of the SCSI spec so we can safely
2358 					 * ignore SAVE/RESTORE pointers calls.
2359 					 *
2360 					 * Unfortunately, some disks violate the SCSI spec and
2361 					 * don't issue the required SAVE_POINTERS message before
2362 					 * disconnecting, and we have to break spec to remain
2363 					 * compatible.
2364 					 */
2365 				case SAVE_POINTERS:
2366 				case RESTORE_POINTERS:
2367 					/* Accept message by clearing ACK */
2368 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2369 					break;
2370 				case EXTENDED_MESSAGE:
2371 /*
2372  * Extended messages are sent in the following format :
2373  * Byte
2374  * 0            EXTENDED_MESSAGE == 1
2375  * 1            length (includes one byte for code, doesn't
2376  *              include first two bytes)
2377  * 2            code
2378  * 3..length+1  arguments
2379  *
2380  * Start the extended message buffer with the EXTENDED_MESSAGE
2381  * byte, since spi_print_msg() wants the whole thing.
2382  */
2383 					extended_msg[0] = EXTENDED_MESSAGE;
2384 					/* Accept first byte by clearing ACK */
2385 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2386 					dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2387 
2388 					len = 2;
2389 					data = extended_msg + 1;
2390 					phase = PHASE_MSGIN;
2391 					NCR5380_transfer_pio(instance, &phase, &len, &data);
2392 
2393 					dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2394 
2395 					if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2396 						/* Accept third byte by clearing ACK */
2397 						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2398 						len = extended_msg[1] - 1;
2399 						data = extended_msg + 3;
2400 						phase = PHASE_MSGIN;
2401 
2402 						NCR5380_transfer_pio(instance, &phase, &len, &data);
2403 						dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2404 
2405 						switch (extended_msg[2]) {
2406 						case EXTENDED_SDTR:
2407 						case EXTENDED_WDTR:
2408 						case EXTENDED_MODIFY_DATA_POINTER:
2409 						case EXTENDED_EXTENDED_IDENTIFY:
2410 							tmp = 0;
2411 						}
2412 					} else if (len) {
2413 						printk("scsi%d: error receiving extended message\n", instance->host_no);
2414 						tmp = 0;
2415 					} else {
2416 						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2417 						tmp = 0;
2418 					}
2419 					/* Fall through to reject message */
2420 
2421 					/*
2422 					 * If we get something weird that we aren't expecting,
2423 					 * reject it.
2424 					 */
2425 				default:
2426 					if (!tmp) {
2427 						printk("scsi%d: rejecting message ", instance->host_no);
2428 						spi_print_msg(extended_msg);
2429 						printk("\n");
2430 					} else if (tmp != EXTENDED_MESSAGE)
2431 						scmd_printk(KERN_INFO, cmd,
2432 							"rejecting unknown message %02x\n",tmp);
2433 					else
2434 						scmd_printk(KERN_INFO, cmd,
2435 							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2436 
2437 					msgout = MESSAGE_REJECT;
2438 					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2439 					break;
2440 				}	/* switch (tmp) */
2441 				break;
2442 			case PHASE_MSGOUT:
2443 				len = 1;
2444 				data = &msgout;
2445 				hostdata->last_message = msgout;
2446 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2447 				if (msgout == ABORT) {
2448 					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2449 					hostdata->connected = NULL;
2450 					cmd->result = DID_ERROR << 16;
2451 					collect_stats(hostdata, cmd);
2452 					cmd->scsi_done(cmd);
2453 					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2454 					return;
2455 				}
2456 				msgout = NOP;
2457 				break;
2458 			case PHASE_CMDOUT:
2459 				len = cmd->cmd_len;
2460 				data = cmd->cmnd;
2461 				/*
2462 				 * XXX for performance reasons, on machines with a
2463 				 * PSEUDO-DMA architecture we should probably
2464 				 * use the dma transfer function.
2465 				 */
2466 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2467 				if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2468 					NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2469 					dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2470 					return;
2471 				}
2472 				break;
2473 			case PHASE_STATIN:
2474 				len = 1;
2475 				data = &tmp;
2476 				NCR5380_transfer_pio(instance, &phase, &len, &data);
2477 				cmd->SCp.Status = tmp;
2478 				break;
2479 			default:
2480 				printk("scsi%d : unknown phase\n", instance->host_no);
2481 				NCR5380_dprint(NDEBUG_ALL, instance);
2482 			}	/* switch(phase) */
2483 		}		/* if (tmp * SR_REQ) */
2484 		else {
2485 			/* RvC: go to sleep if polling time expired
2486 			 */
2487 			if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2488 				NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2489 				dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2490 				return;
2491 			}
2492 		}
2493 	}			/* while (1) */
2494 }
2495 
2496 /*
2497  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2498  *
2499  * Purpose : does reselection, initializing the instance->connected
2500  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2501  *      nexus has been reestablished,
2502  *
2503  * Inputs : instance - this instance of the NCR5380.
2504  *
2505  * Locks: io_request_lock held by caller if IRQ driven
2506  */
2507 
2508 static void NCR5380_reselect(struct Scsi_Host *instance) {
2509 	NCR5380_local_declare();
2510 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2511 	 instance->hostdata;
2512 	unsigned char target_mask;
2513 	unsigned char lun, phase;
2514 	int len;
2515 	unsigned char msg[3];
2516 	unsigned char *data;
2517 	Scsi_Cmnd *tmp = NULL, *prev;
2518 	int abort = 0;
2519 	NCR5380_setup(instance);
2520 
2521 	/*
2522 	 * Disable arbitration, etc. since the host adapter obviously
2523 	 * lost, and tell an interrupted NCR5380_select() to restart.
2524 	 */
2525 
2526 	NCR5380_write(MODE_REG, MR_BASE);
2527 	hostdata->restart_select = 1;
2528 
2529 	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2530 	dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2531 
2532 	/*
2533 	 * At this point, we have detected that our SCSI ID is on the bus,
2534 	 * SEL is true and BSY was false for at least one bus settle delay
2535 	 * (400 ns).
2536 	 *
2537 	 * We must assert BSY ourselves, until the target drops the SEL
2538 	 * signal.
2539 	 */
2540 
2541 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2542 
2543 	/* FIXME: timeout too long, must fail to workqueue */
2544 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2545 		abort = 1;
2546 
2547 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2548 
2549 	/*
2550 	 * Wait for target to go into MSGIN.
2551 	 * FIXME: timeout needed and fail to work queeu
2552 	 */
2553 
2554 	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2555 		abort = 1;
2556 
2557 	len = 1;
2558 	data = msg;
2559 	phase = PHASE_MSGIN;
2560 	NCR5380_transfer_pio(instance, &phase, &len, &data);
2561 
2562 	if (!(msg[0] & 0x80)) {
2563 		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2564 		spi_print_msg(msg);
2565 		abort = 1;
2566 	} else {
2567 		/* Accept message by clearing ACK */
2568 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2569 		lun = (msg[0] & 0x07);
2570 
2571 		/*
2572 		 * We need to add code for SCSI-II to track which devices have
2573 		 * I_T_L_Q nexuses established, and which have simple I_T_L
2574 		 * nexuses so we can chose to do additional data transfer.
2575 		 */
2576 
2577 		/*
2578 		 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2579 		 * just reestablished, and remove it from the disconnected queue.
2580 		 */
2581 
2582 
2583 		for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2584 			if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2585 			    ) {
2586 				if (prev) {
2587 					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2588 					prev->host_scribble = tmp->host_scribble;
2589 				} else {
2590 					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2591 					hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2592 				}
2593 				tmp->host_scribble = NULL;
2594 				break;
2595 			}
2596 		if (!tmp) {
2597 			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2598 			/*
2599 			 * Since we have an established nexus that we can't do anything with,
2600 			 * we must abort it.
2601 			 */
2602 			abort = 1;
2603 		}
2604 	}
2605 
2606 	if (abort) {
2607 		do_abort(instance);
2608 	} else {
2609 		hostdata->connected = tmp;
2610 		dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2611 	}
2612 }
2613 
2614 /*
2615  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2616  *
2617  * Purpose : called by interrupt handler when DMA finishes or a phase
2618  *      mismatch occurs (which would finish the DMA transfer).
2619  *
2620  * Inputs : instance - this instance of the NCR5380.
2621  *
2622  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2623  *      nexus has been reestablished, on failure NULL is returned.
2624  */
2625 
2626 #ifdef REAL_DMA
2627 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2628 	NCR5380_local_declare();
2629 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata * instance->hostdata);
2630 	int transferred;
2631 	NCR5380_setup(instance);
2632 
2633 	/*
2634 	 * XXX this might not be right.
2635 	 *
2636 	 * Wait for final byte to transfer, ie wait for ACK to go false.
2637 	 *
2638 	 * We should use the Last Byte Sent bit, unfortunately this is
2639 	 * not available on the 5380/5381 (only the various CMOS chips)
2640 	 *
2641 	 * FIXME: timeout, and need to handle long timeout/irq case
2642 	 */
2643 
2644 	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2645 
2646 	NCR5380_write(MODE_REG, MR_BASE);
2647 	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2648 
2649 	/*
2650 	 * The only places we should see a phase mismatch and have to send
2651 	 * data from the same set of pointers will be the data transfer
2652 	 * phases.  So, residual, requested length are only important here.
2653 	 */
2654 
2655 	if (!(hostdata->connected->SCp.phase & SR_CD)) {
2656 		transferred = instance->dmalen - NCR5380_dma_residual();
2657 		hostdata->connected->SCp.this_residual -= transferred;
2658 		hostdata->connected->SCp.ptr += transferred;
2659 	}
2660 }
2661 #endif				/* def REAL_DMA */
2662 
2663 /*
2664  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2665  *
2666  * Purpose : abort a command
2667  *
2668  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2669  *      host byte of the result field to, if zero DID_ABORTED is
2670  *      used.
2671  *
2672  * Returns : 0 - success, -1 on failure.
2673  *
2674  *	XXX - there is no way to abort the command that is currently
2675  *	connected, you have to wait for it to complete.  If this is
2676  *	a problem, we could implement longjmp() / setjmp(), setjmp()
2677  *	called where the loop started in NCR5380_main().
2678  *
2679  * Locks: host lock taken by caller
2680  */
2681 
2682 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2683 	NCR5380_local_declare();
2684 	struct Scsi_Host *instance = cmd->device->host;
2685 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2686 	Scsi_Cmnd *tmp, **prev;
2687 
2688 	printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2689 	scsi_print_command(cmd);
2690 
2691 	NCR5380_print_status(instance);
2692 
2693 	NCR5380_setup(instance);
2694 
2695 	dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2696 	dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2697 
2698 #if 0
2699 /*
2700  * Case 1 : If the command is the currently executing command,
2701  * we'll set the aborted flag and return control so that
2702  * information transfer routine can exit cleanly.
2703  */
2704 
2705 	if (hostdata->connected == cmd) {
2706 		dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2707 		hostdata->aborted = 1;
2708 /*
2709  * We should perform BSY checking, and make sure we haven't slipped
2710  * into BUS FREE.
2711  */
2712 
2713 		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2714 /*
2715  * Since we can't change phases until we've completed the current
2716  * handshake, we have to source or sink a byte of data if the current
2717  * phase is not MSGOUT.
2718  */
2719 
2720 /*
2721  * Return control to the executing NCR drive so we can clear the
2722  * aborted flag and get back into our main loop.
2723  */
2724 
2725 		return 0;
2726 	}
2727 #endif
2728 
2729 /*
2730  * Case 2 : If the command hasn't been issued yet, we simply remove it
2731  *          from the issue queue.
2732  */
2733 
2734 	dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2735 	for (prev = (Scsi_Cmnd **) & (hostdata->issue_queue), tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2736 		if (cmd == tmp) {
2737 			REMOVE(5, *prev, tmp, tmp->host_scribble);
2738 			(*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2739 			tmp->host_scribble = NULL;
2740 			tmp->result = DID_ABORT << 16;
2741 			dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2742 			tmp->done(tmp);
2743 			return SUCCESS;
2744 		}
2745 #if (NDEBUG  & NDEBUG_ABORT)
2746 	/* KLL */
2747 		else if (prev == tmp)
2748 			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2749 #endif
2750 
2751 /*
2752  * Case 3 : If any commands are connected, we're going to fail the abort
2753  *          and let the high level SCSI driver retry at a later time or
2754  *          issue a reset.
2755  *
2756  *          Timeouts, and therefore aborted commands, will be highly unlikely
2757  *          and handling them cleanly in this situation would make the common
2758  *          case of noresets less efficient, and would pollute our code.  So,
2759  *          we fail.
2760  */
2761 
2762 	if (hostdata->connected) {
2763 		dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2764 		return FAILED;
2765 	}
2766 /*
2767  * Case 4: If the command is currently disconnected from the bus, and
2768  *      there are no connected commands, we reconnect the I_T_L or
2769  *      I_T_L_Q nexus associated with it, go into message out, and send
2770  *      an abort message.
2771  *
2772  * This case is especially ugly. In order to reestablish the nexus, we
2773  * need to call NCR5380_select().  The easiest way to implement this
2774  * function was to abort if the bus was busy, and let the interrupt
2775  * handler triggered on the SEL for reselect take care of lost arbitrations
2776  * where necessary, meaning interrupts need to be enabled.
2777  *
2778  * When interrupts are enabled, the queues may change - so we
2779  * can't remove it from the disconnected queue before selecting it
2780  * because that could cause a failure in hashing the nexus if that
2781  * device reselected.
2782  *
2783  * Since the queues may change, we can't use the pointers from when we
2784  * first locate it.
2785  *
2786  * So, we must first locate the command, and if NCR5380_select()
2787  * succeeds, then issue the abort, relocate the command and remove
2788  * it from the disconnected queue.
2789  */
2790 
2791 	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2792 		if (cmd == tmp) {
2793 			dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2794 
2795 			if (NCR5380_select(instance, cmd, (int) cmd->tag))
2796 				return FAILED;
2797 			dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2798 
2799 			do_abort(instance);
2800 
2801 			for (prev = (Scsi_Cmnd **) & (hostdata->disconnected_queue), tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2802 				if (cmd == tmp) {
2803 					REMOVE(5, *prev, tmp, tmp->host_scribble);
2804 					*prev = (Scsi_Cmnd *) tmp->host_scribble;
2805 					tmp->host_scribble = NULL;
2806 					tmp->result = DID_ABORT << 16;
2807 					tmp->done(tmp);
2808 					return SUCCESS;
2809 				}
2810 		}
2811 /*
2812  * Case 5 : If we reached this point, the command was not found in any of
2813  *          the queues.
2814  *
2815  * We probably reached this point because of an unlikely race condition
2816  * between the command completing successfully and the abortion code,
2817  * so we won't panic, but we will notify the user in case something really
2818  * broke.
2819  */
2820 	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2821 			"         before abortion\n", instance->host_no);
2822 	return FAILED;
2823 }
2824 
2825 
2826 /*
2827  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2828  *
2829  * Purpose : reset the SCSI bus.
2830  *
2831  * Returns : SUCCESS
2832  *
2833  * Locks: host lock taken by caller
2834  */
2835 
2836 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2837 {
2838 	struct Scsi_Host *instance = cmd->device->host;
2839 
2840 	NCR5380_local_declare();
2841 	NCR5380_setup(instance);
2842 	NCR5380_print_status(instance);
2843 
2844 	spin_lock_irq(instance->host_lock);
2845 	do_reset(instance);
2846 	spin_unlock_irq(instance->host_lock);
2847 
2848 	return SUCCESS;
2849 }
2850